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A light spot on the leaf of Nelumbium
V. Vouk
; Hrvatska
M. Njegovan
; Hrvatska
Sažetak
The authors point to a special light spot, which is situated in the middle of the leaf of Nelumbium luteum Wild., which is cultivated in the pond of the Botanical Garden of the University in Zagreb. As the previous investigators of the anatomy of Nelumbium’s leaf (Wigand-Dennert) have neither described this spot precisely, nor have they given any explanation, the authors have examined the anatomy of this organ and tried to explain it.
The light spot is especially characterised by unusually big stomata (56X32), which are more than twice as big as the ones on the blade (lamina) of the leaf. Their number is, according to this, much smaller (cca 70 pro mm'2) than on the leaf itself (cca 550 pro mm2). The stomata are built of guard cells, which have no thickenings, neither anticlinal nor periclinal, and contain a lot of starch. Directly attached to the stomata is the lacunose parenchyma and the inercellular lacunes-system of the petiole. The stomata are very permeable for gases, what can easyly be shown by blowing the air through the petiole of a leaf which is placed under the water. This, and the elementary test with the cobaltpaper, show that the light spot is a pneumathodic organ sui generis — which deals as »a chimney« on the leaf of Nelumbium to intensify the transpiration and exchange of gases as a special hydrophytic adaptation.
The details of the structure of this organ in comparation with the anatomy of the leaf can be seen on the added figures.
Ključne riječi
Hrčak ID:
152592
URI
Datum izdavanja:
31.12.1949.
Posjeta: 871 *